Expansible reamer



Feb. 3, 1931.

F. s. HARTwELL 1,791,205

EXPANSIBLE REAMER Filed July 23, 1926 Patented Feb. 3, 1931 TAS ' Limos" i` orifice EXPANSIBLE BEAMER Application sied July 231926. vserieu No. 124,488.

My invention relates to combination borl ing and reaming tools and particularly to suchas are employed in heavy foundry and other Work which subjects the tool to unusus al Wear and strain. It is of course to be understood, however, that the invention is not limited to tools oi this class, but also appertains to tools which arefdesigned for illustrating Whatl novv regard as a preferred lighter Work. 1c In all inserted blade reaming andboring tools vvith vvhich I am familiar-the'cutting blades are held in place by nieansoi a multiplicity of locking or adjusting screws. Not only is it a painstaking and time consuming task to` properly adjust the blades of such reamers, but further ,much ditliculty is eX- perienced in maintaining the desired adjustment, particularly when the tfoolisV subjected tovery heavy usage as for instance, furnace section reaming or the like. The strain of this hard and continued use causesthe blades to become loose or iinseated.V Reaming ma-v chines commonly include four six blade roam ers, the blades of each reamer being securedl by not less than twelve holding'screws making a ltotal otforty-'eightscrews for each machine. Theloosening and tightening of thesescrevvgfor even minor readjustment, results ina great loss of timek as Will bei-sad ily appreciated.' Furthermoraaloss of ad-g justment of the. blades While the tool is in use is likely to result in spoiling'of the Work. It is theretorefthe primary objectA of my invention to overcome the aforementionedy difficulties andto provide a novel blade fas'- toning means Which will eliminate the neces ,sity for the numerous fastening screws or analogous elements ofthe prior art; one

vvhichvvill permit of ready adjustment or re- 40 moval ofthe bladesv as occasion may. re-

quire and which is adapted to hold the blades rigidly in a set position even When the tool y is subjected to continuous and very heavy usage for a long period of time;

The invention also aims to provide a tool of this class which is of unusually simple and durable construction, comprising but a miniL mum number of easily assembled parts, and which will be relatively inexpensive to ufacture.' f .f y

tools. o't the 'solid head type,

. to slidingly lit in grooves.Y "i

The various features of novelty which characterize thek invention are pointed out' With particularity. vin the claims-annexed to and formingr a part of this specification.

Yllowever,*tera better understanding ofthe invention reference should be had totheacvco-mpanying drawings in connectionfvvith the :tollovving descriptive matter, the.. drawings l embodiment of the"invent-ion.l It is `of course to be understood, however, that `I do not propose to limit myself to this disclosure but reserve the right to'inake such kchanges and modifications asiaiily fallwithin the c. spirit and scopo of theinveiitionV as claimed. ln thedrawings,` i Figure 1 is a vertical longitudinal sectional View through areanier constructed in accV rdance With the invention;

Figure 2 is an endelevation of theim- 70 proved reainer; l y Y e f e y Figure 3 isa group perspective illustrating an expansible ring and .one of the blades embodied inthe invention. y .v

have shown, for the' purpose of. illustra' 75 tion, a tool of the shell type but it is to be 'understood that it is eeually applicable to rThe reamerkhead proper,designated at v1, is of circular'cross section, beingpi'ovided 80 with an externally threaded portion-2er:- tending from its rear end throughout the major portion of its length and terminating at a shoulder 3 from whence the Wall ofthe head tapers torvvardlyand outwardly in truste-conical fashion as indicated at 1l.

e `The front endof the head is provided with a plurality of longitudinally extending and oircumferentially spaced surface-grooves 5 vhaving undercut Wall portions indicatedhat 5a. These ygrooves 5` haveV sloping bottoms 5P andincrease in depth in the direction ofthev rear endof the headasclearly shovvn in Fig.V

1, said groove terminating at a point intervmediate the ends of the threaded portion 2.

Cutting blades-6 are insertible in the grooves 5 from the outer-ends and the major portions of theblades are substantially Wedge shaped in cross section as showninFig. 2l whereby L 1mi veisely of their aXes whereby to effect a binding of said cutters against the undercut walls of their grooves and lock them against movement, and a backing nut threaded on said head and engagingthe ends of said cutters for adjusting the same longitudinally in their grooves. i

3. A reamer comprising a head having grooves in its outer surface and provided with undercut walls, said grooves being open at oneend rof said head and increasing'in depth in the direction of their other ends, radially projecting cutters carried by said head and insertible in said grooves, the undercut walls of said grooves engaging said cutters to limit radial Youtward movement thereof, said head having a circumferential groove in its first mentioned end and communicating with said first named grooves, said circumferential groove having lateral enlargement at its inner side defining a shoulder, a splitclamping ring insertible in sai-d circumferential groove and having lateral projections engagea-ble with said shoulder to hold said ring in place, and a wedge screw working in said head and bearing against thesplit ends of said ring for circumferentially spreading the same to frictionally engage said cutters transversely oftheir axes where* by toefect a binding of said cutters against the undercut walls of their grooves Vand loch them against movement. v

1i. A reamer comprising a head having grooves inits outer surface and provided with undercut walls, said grooves b ing open at one end of said head, radially projectingl cutters carried by said head and insertible iii said grooves, the undercut walls of said,

5. A reamer comprising an integral headV having grooves in its outer surface and 'provided with undercut walls,.said grooves being open at one end of said head and increasing in depth in the direction of their other ends, radially projectingv cutters carried by said head and nsertible in said grooves, the undercut walls of said grooves .engaging said cutters to limit radial outward movement thereof, and a contractible clamping element within said headL and engageable with said cutters through said grooves to urge the cutters against the undercut walls lof said grooves for rigidly binding the same againsty movement in their grooves.

6. The combination with a'reamerliead, the radially projecting blades, and the means for holding said blades against'radial outward movement;'of a split ring insertible in the end ofsaid head and` designed to bear against the inner edges of said blades for the full width thereof, means for expanding said ring to bind against the blades and hold them in place, said head having an annular groove for the reception of said ring, the back of said groove being provided with a shoulder, and said ring having a laterally projecting part designed to engage said shoulder whereby the ring and head will be held assembled. 7. The combination with a reamer head, the radially projecting blades and the means for holding said blades against radial out* ward movement; of a split ring insertible in the end of said head and designed to bear against the inner edges of said blades for the full width v thereof, means for expanding .said ring to bind against the blades and hold them in place, said means comprising a wedge member carried byv said head and in- "sertible between the split ends of said ring,

and said wedge member serving to hold said C: ring and head assembled.

8. The combination with av reamer head,

for holding said blades against radial outward movement; of a split ring insertible iii the end ,of said head and designed to bear against the inner edges of said blades for the fullwidth thereof, means for expanding said ring to bind against thevblades and hold them the'radially projecting blades and the means iop.

outward radial movement, Yan expansible multiple blade clamping device comprising a split ring removably carried within saidr head, said head overlying and protecting .said clamping means, the latter being contractible for insertion into said headfrom one end thereof to engage said blades to effect a binding thereof in the blade holding portions of said head,a radially extending outer angefportion carried by'said bladefY clamping means, and the `clamping means receiving opening of said head having recess to receive said flange portion whereby the ring will be removably locked within said head.l f Y -ln testimony whereof I affix my signature. f FLOYD S. HARTVVELL. l 

